Tugboat

A tugboat, is used to manoeuvre, mainly by towing other vessels in harbours, over the open sea, rivers and canals. They are used to tow barges, disabled ships other equipment like towboats.

A tugboat refers to a recreational boat that resembles a tug in shape, but is not designed for towing.

Tugboats are strong for their size. Early tugboats had used steam engines, but, nowadays diesel engines are used. Tugboat engines normally produce 750 to 3000 hp, but larger boats can have power ratings up to 25 000 hp. The engines are regularly used in railroad engines, but naturally drive the propellor mechanically as a substitute of converting the engine output to power electric motors, as is general for railroad engines. For safety, tugboats engines feature two of each important part for redundancy.

Tugboats are very much maneuverable and different propulsion systems have been developed to boost manoeuvrability and increase safety. The first tugs were fitted with paddle wheels but these were soon replaced by propeller-driven tugs. Kort nozzles have been added to increase thrust per hp. This was said by the nozzle-rudder which omitted the need for a conventional rudder.

Raft

A raft is some flat floating structure for travel over water. It is the most basic of boat design, characterized by the lack of a hull. Instead, rafts are kept afloat using any mixture of buoyant materials such as wood, sealed barrels, or overstated air chambers. Traditional or antique rafts are constructing of wood or reeds. Present rafts may also use pontoons, drums, or extruded polystyrene blocks. Hot-air balloon rafts use durable, multi-layered rubberized fabrics, Depending on it’s utilize and size; it may contain a superstructure, masts, or rudders.
Timber rafting is used by the logging industry for the carrying of logs, by tying them together into rafts, and traveling or pulling them down a river. This method was very common up until the center of the 20th century but is now hardly used.
The type of raft used for spare time rafting is almost completely an inflatable boat, manufactured of flexible materials for use on whitewater.

Wherry

The Norfolk wherry is a black-sailed trader, kind of boat on The Broads in Norfolk. It is double-ended with the pole steeped well forward, tinted black with a single gaff sail. Mostly clinker-built, it would carry about 25 tons of goods.
Wherries were able to arrive at better boats just off coast and take their cargoes off to be transported inland through the broads and the rivers.
Before wherries, there was the Norfolk Keel, a quadrangle rigged, transom sterned clinker-built boat, 54 feet by 14 feet, and able to carry 30 tons of goods. The keel had been built since the middle Ages and the plan probably went back to the Viking invasion. After 1800, the Norfolk Keel (or 'keel wherry') disappeared, partly since a wherry could be sailed with fewer crew, and it had limited maneuverability and lacked speed.
A special wherry wheelbarrow was used to unpack cargo, e.g. stone, from the wherries. It was made from wood and strengthens with iron bands. It had no legs; therefore it could be rested on the 11 inches wide plank on the surface of the wherry.